The economy is driven in part by the transport of goods and materials from one location to another. The use of durable and inexpensive containers for transporting certain materials has grown over the years. For example bulk containers, commonly known as bulk bags, have been widely accepted for use in receiving, storing, transporting, and discharging flowable dry materials of various types. Bulk Bags provide an economical and efficient means to load, pack, store, and discharge a wide range of particulate materials, such as chemical feedstocks, silicates, and mineral powders, building materials such as cement, sand, and cinder ash, and granulated food materials such as grains, cereals, flours, sugars, nuts, and so on.
The preferred material employed in early modern bulk bags was polyvinyl chloride (PVC). While providing strength, durability and flexibility, PVC was replaced by polypropylene because of it was more durable, reliable, and resilient. Polypropylene also possesses improved chemical resistance. Bulk bags are now typically made of woven polypropylene. Bulk bags are generally of rectangular form featuring four side panel construction but may possess cross-sectional alternative tubular geometries and perimetric configurations, e.g. polygonal or circular/cylindrical construction. Typical bulk bags also incorporate integrated lifting loops sized and adapted to cooperate with conventional lifting equipment, e.g., hoists, cranes, forklift truck lifting tines, etc. The lifting loops are employed to manipulate and move a bag to and from a select destination, e.g., a filling station, a transport pallet, or a discharge device/hopper. Many variations of bulk containers exist such as those illustrated in U.S. Pat. Nos. 5,685,644, 6,220,755 and 6,179,467.
In the context of bulk bag discharge, one common technique relies on gravity to empty a bag once it has been moved over the opening of a discharge bin/hopper and the bottom of the bag is pierced or cut. The bag, for example may be lifted from a transport pallet using a forklift by engaging the lifting loops with the tines, positioning the bulk bag over a discharge opening of an underlying hopper and dropping the bag onto an integrated piercing/puncture element. The bag bottom is cut open and the contents discharged directly into the receiving bin/hopper. Exemplary devices of this nature are depicted in U.S. Pat. Nos. 6,293,318 and 5,405,053.
In bulk bag content discharge operations, particularly when involving material comprising fine comminuted/pulverized particles, creates a dust cloud which can present a danger for fire/explosion, a potential health hazard, and a deleterious environment for machinery. Industrial dust explosions and fires are not uncommon regardless of the otherwise innocent nature of the material involved. Concerns relating to dust and combustion are well known in the chemical industry but also exist in other seemingly less dangerous industries, as for example, in the food processing industry, e.g., sugar, flour, and grain, in the building products industry, e.g., sawdust and cement, and the textile industry, e.g., cotton and fibers. Powders that are normally quite stable in bulk form, when dispersed as a dust cloud, in the worst case, are combustible and become explosive. In in lesser concentrations, unabated dust exposure constitutes a potential health risk to personnel in the vicinity of the content receiving port/bin/chute/hopper and causes unnecessary mechanical wear and damage that may adversely impact the functional integrity of proximate equipment.
Indeed, the dangers being so recognized have led to governmental and organizational dust abatement standards issued, for example, by the National Fire Protection Association (NFPA), the Occupational Safety & Health Administration (OSHA) and other national and international bodies. Consequently, care must be exercised when discharging powdered/granulated materials stored and/or transported in bulk bags to avoid creation of an undesirable dust cloud.
Regardless of the foregoing risks, bulk bags remain one of the most efficient and economical containers for transporting large, specific amounts of granulated/powered materials. With the continued and a projected increase in use of bulk bags, it is important to minimize such potential risks.
In response to the problem, dust remediation systems have been developed as associated with the discharge equipment that rely on relatively expensive and complex vacuum systems and the like. However, a need still exists for a relatively inexpensive, uncomplicated, easily utilized solution for abatement of dust cloud migration associated with bulk bag discharge.